Terminal applicator machines are widely used in the industry to attach electrical terminals to conductors. These terminal applicators are typically secured in a press which supplies the power and motion that operates the applicator. The applicator may be used manually where an operator inserts an already prepared wire end into the crimping area between a crimping tool and an anvil containing a terminal and holds the wire in place while activating the press to complete the termination. Alternatively, the terminal applicator and associated press may be attached to a host machine, such as a lead maker, where the prepared wire end is automatically presented to the applicator tooling for termination. These terminal applicators typically feed a strip of terminals along a guide rail into a workstation where one of the terminals is positioned over an anvil. The wire, its end having been previously stripped of insulation, is positioned in the workstation and the apparatus is activated to cause crimping tools to engage and crimp the tabs of the terminal onto the end of the wire. There are two variations of terminal feeding arrangements, depending on the arrangement of the terminals on their carrier strip. Carrier strips can be designed for either side feed or end feed in conformance with the configuration of the terminal. Each presents its own unique characteristics when considering the design of a terminal hold down for controlling and limiting movement of the terminal during the actual crimping of the terminal onto the wire.
An example of a prior art terminal hold down for an end feed application is shown in FIG. 1. There a partial view is shown of a ram 2 of a terminal applicator having terminal crimping tooling 4 and a terminal hold down 6, both of which are carried by the ram during the crimping process. The hold down 6 is in sliding engagement with an opening 8 formed in the ram 2 so that the hold down is free to undergo limited movement in the directions indicated by the arrows 10 and 12. An elastic member, not shown, is positioned within the opening 8 so that it urges the hold down 6 in the direction of the arrow 12. The hold down 6 includes a terminal hold down surface 14 and a projection 16 having a stop surface 18 spaced from the surface 14 a specific amount. This spacing is chosen so that, when the ram 2 has reached the end of its stroke and the tooling 4 is in crimping engagement with a terminal, the stop surface 18 has engaged a fixed surface, not shown, and the hold down surface 14 is in a desired close proximity to the terminal for limiting adverse movement of the terminal. This type hold down 6 must necessarily have the projection 16 and stop surface 18 accurately machined so that the spacing of the surface 18 from the surface 14 corresponds to the requirements of the terminal being crimped. Every terminal having different spacing requirements necessitates a hold down 6 with a unique spacing of the surface 18 from the surface 14. This results in many different, relatively complex, hold downs being manufactured and maintained and, of course, their corresponding substantial cost.
An example of a prior art terminal hold down for a side feed application is shown in FIG. 2. There a partial view is shown of a ram 24 of a terminal applicator having terminal crimping tooling 26 and a terminal hold down 28, both of which are carried by the ram during the crimping process. The hold down 28 has a hold down surface 30 and is constructed of a urethane and includes a stud 32 that is threaded into a hole in a member 34 attached to the ram 24 and a lock nut 36 arranged to lock the stud in a desired position. The hold down 28 is positioned so that when the ram 24 has reached the end of its stroke and the tooling 26 is in crimping engagement with a terminal, the hold down surface 30 is in a desired close proximity to the terminal for limiting adverse movement of the terminal. This arrangement requires that the hold down 28 be positioned very accurately so that the terminal is not damaged when the ram 24 is fully extended during crimping. The urethane material provides a slightly pliable surface to aid in preventing damage of the terminal should an out of tolerance condition be encountered. This material, however, has the disadvantage of becoming warn during use, requiring occasional replacement. Another disadvantage is that each time the crimp height is adjusted, the position of the hold down 28 must be readjusted. This can be a tedious operation during initial set up of the applicator.
What is needed is a terminal applicator machine having a simple and inexpensive terminal hold down device that will work for a wide range of different terminal sizes, in both end feed and side feed application, and that need not be readjusted upon adjusting the crimp height of the applicator.